Cement mortar and concrete compositions are well known and have been adapted for innumerable uses, from heavy construction materials as in concrete blocks, bricks, foundations for structures, columns for high story buildings, and road and highway materials to lighter construction materials including household bonding materials.
A mortar is generally a cement mixed with a fine aggregate filler and water. A concrete differs from a mortar in that it additionally contains a coarse aggregate filler. The most common cements used in mortars and concretes are hydraulic cements. These are cements that require water in order to cure or harden. The choice of the particular hydraulic cement depends upon the particular end use and properties desired. In describing the cement component used in accordance with this invention, conventional Portland cement will be referred to hereinafter as an illustrative example to simplify the description of the invention.
Aggregate fillers are included in mortars and concretes generally to economize the cost of the compositions as well as to reduce shrinkage of the compositions upon curing.
With respect to the economical aspects of using fillers, it is well known that conventional fillers are less expensive than cement components and so fillers generally increase the volume coverage of a given amount of cement.
Aggregate fillers, as used in conventional mortars and concretes, have been considered inert and passive components with respect to the properties of the cured mortar or concrete. The chemical make-up or physical structure of aggregate fillers, other than their particle size, has not been considered to appreciably improve the overall strength characteristics of a concrete or mortar product.
In the past, in order to improve the strength properties of a given mortar or concrete, attention has been directed to varying the ratios of the components and adding other materials.
It has now been discovered that a particular chemical treatment of conventional aggregate materials will substantially improve the compressive strength and other properties of mortars and concretes.